drm/sti/sti_hdmi: convert to struct drm_edid

drm/sti/sti_hdmi: convert to struct drm_edid

Prefer the struct drm_edid based functions for reading the EDID and
updating the connector.

The functional change is that the CEC physical address gets invalidated
when the EDID could not be read.

v2: Use drm_edid_read() instead of drm_edid_read_ddc() (Sima)

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/25879a0183e30792bf0d63bdf56a03f11018e4a3.1724348429.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>